arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0705.0364nlin.PS
收藏

光晶格中线性耦合玻色-爱因斯坦凝聚体中的对称和非对称孤子

Symmetric and asymmetric solitons in linearly coupled Bose-Einstein condensates trapped in optical lattices

Arthur Gubeskys, Boris A. Malomed

摘要:

本文研究了两个平行准一维陷阱系统中的自发对称性破缺,该系统装有光晶格并填充有玻色-爱因斯坦凝聚体。这些核通过隧穿线性耦合。分析相应的系统的线性耦合Gross-Pitaevskii方程(GPE)表明,光谱带隙的单个GPE分裂成子带隙。研究了两个陷阱中的吸引(AA)和排斥(RR)非线性的情况下,两个组件的BEC孤子的对称性破缺;混合的情况下,排斥在一个陷阱和吸引在其他(RA),被认为是太。在所有的情况下,稳定的非对称孤子被发现,分叉从对称或反对称的(和不稳定的),分别在AA和RR系统。在任何一种情况下,双稳定性预测,与nonbifurcating稳定的分支,反对称或对称,共存与不对称的。由于分叉而失稳的孤子往往会重新排列成稳定的非对称孤子。还研究了两个核中的OL之间的相位失配的影响。也被认为是一个相关的模型,在一个单一的核心陷阱与OL的二元BEC,假设这两个物种(代表不同的自旋状态的同一个原子)耦合的线性相互转换。在这种情况下,如果物种间的非线性相互作用比物种内的非线性相互作用更强,AA和RR模型中的破缺分岔就会发生切换。

英文摘要:

We study spontaneous symmetry breaking in a system of two parallel quasi-one-dimensional traps, equipped with optical lattices (OLs) and filled with a Bose-Einstein condensate (BEC). The cores are linearly coupled by tunneling. Analysis of the corresponding system of linearly coupled Gross-Pitaevskii equations (GPEs) reveals that spectral bandgaps of the single GPE split into subgaps. Symmetry breaking in two-component BEC solitons is studied in cases of the attractive (AA) and repulsive (RR) nonlinearity in both traps; the mixed situation, with repulsion in one trap and attraction in the other (RA), is considered too. In all the cases, stable asymmetric solitons are found, bifurcating from symmetric or antisymmetric ones (and destabilizing them), in the AA and RR systems, respectively. In either case, bi-stability is predicted, with a nonbifurcating stable branch, either antisymmetric or symmetric, coexisting with asymmetric ones. Solitons destabilized by the bifurcation tend to rearrange themselves into their stable asymmetric counterparts. The impact of a phase mismatch, between the OLs in the two cores is also studied. Also considered is a related model, for a binary BEC in a single-core trap with the OL, assuming that the two species (representing different spin states of the same atom) are coupled by linear interconversion. In that case, the symmetry-breaking bifurcations in the AA and RR models switch their character, if the inter-species nonlinear interaction becomes stronger than the intra-species nonlinearity.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑